JPH0858124A - Thermal transfer printing apparatus - Google Patents

Abstract

PURPOSE: To provide a re-transfer type thermal transfer printing apparatus capable of applying printing to the entire surface of recording paper without increasing the cost. CONSTITUTION: The ink of an ink film 1 is transferred to an intermediate transfer film 7 by a thermal head 3. The ink image transferred to the intermediate transfer film 7 and recording paper 2 are fed to the gap between a heating roller 11 and a re-transfer roller 17 to be superposed one upon another and the ink image is re-transferred to the recording paper 2 by the heat of the heating roller 11. The intermediate transfer film 7 passed through the nip between holding guides 18a, 18b is steeply raised by the rear end part of the holding guide 18a to be separated from the recording paper 2. The separated recording paper 2 is fed to a discharge port by feed rollers 19a, 19b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer printing apparatus for transferring a meltable or sublimable ink onto a recording medium,
In particular, the present invention relates to a retransfer thermal transfer printing apparatus that temporarily forms an ink image on an intermediate transfer film and then transfers the ink image formed on the intermediate transfer film to a recording medium.

[0002]

2. Description of the Related Art A fusible or sublimable ink applied to an ink film is transferred to an intermediate transfer film to form an ink image on the intermediate transfer film, and then the ink image formed on the intermediate transfer film is transferred. A retransfer type thermal transfer printing apparatus for transferring onto a recording medium has been considered and various proposals have been made. As an example of this type of thermal transfer printing apparatus, Japanese Patent Publication No. 6-26904 or JP-A-5-20 is known.
There is one described in No. 1037. Fig. 3 is Japanese Patent Publication 6-26
904 is a thermal transfer printing apparatus, and FIG. 4 is a thermal transfer printing apparatus described in JP-A-5-201037. The conventional thermal transfer printing apparatus will be described below with reference to FIGS. 3 and 4.

In FIG. 3, the ink film 1 is stretched between a supply reel 5 and a take-up reel 6 with the ink application surface facing the platen roller 4 side. The intermediate transfer film 7 is stretched between the supply reel 8 and the take-up reel 9 with its conveying path guided by the guide roller 10 and the heating roller 11. A thermal head 3 is arranged on the outer side (base film side) of the ink film 1, and the ink film 1 and the intermediate transfer film 7 are brought into close contact with each other between the thermal head 3 and the platen roller 4. The recording paper 2 which is an image receiver is wound around the winding roller 12, and the recording paper 2 and the intermediate transfer film 7 are brought into close contact with each other between the heating roller 11 and the winding roller 12.

The recording operation on the recording paper 2 is performed as follows. The platen roller 4 is rotated in the direction of the arrow while pressing the thermal head 3 against the platen roller 4, and the ink film 1 and the intermediate transfer film 7 are conveyed in the direction of the arrow. At this time, the ink of the ink film 1 is melted or sublimated by applying a predetermined current to the thermal head 3 and transferred to the intermediate transfer film 7. Next, the intermediate transfer film 7 is conveyed in the direction of the arrow to convey the ink image 1a to the heating roller 11. The ink image 1a formed on the intermediate transfer film 7 and the recording paper 2 are superposed, the heating roller 11 and the winding roller 12 are rotated in the direction of the arrow, and the heating roller 11 is heated, whereby the recording paper 2 is formed. The ink image 1a on the intermediate transfer film 7 is transferred.

FIG. 4 shows the ink image 1a on the intermediate transfer film 7.
2 shows a portion for transferring the sheet onto the recording paper 2. The conveyance direction of the intermediate transfer film 7 is bent upward by the blade 13, and the recording sheet 2 is conveyed downward, whereby the ink image 1a of the intermediate transfer film 7 is transferred to the recording sheet 2.

[0006]

By the way, in the conventional thermal transfer printing apparatus shown in FIG. 3, a clamper for holding the leading end of the recording paper 2 for winding the recording paper 2 around the winding roller 12 is provided, or an air compressor or the like is provided. Therefore, it is necessary to wind the recording paper 2 around the winding roller 12. If a clamper is provided to hold the recording paper 2, a holding margin is required, so that the leading edge of the recording paper 2 cannot be printed and the entire surface of the recording paper 2 cannot be printed. Although this problem can be solved by using an air compressor or the like, the cost becomes high. On the other hand, in the conventional thermal transfer printing apparatus shown in FIG. 4, a holding portion 14 is provided at the front end of the recording paper 2 so that the recording paper 2 is not guided upward together with the intermediate transfer film 7 as shown by the broken line. It is necessary to pull the recording sheet 2 downward by the section 14. Therefore, also in this case, it is impossible to print on the leading end portion of the recording paper 2, and it is impossible to print on the entire surface of the recording paper 2.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a retransfer type thermal transfer printing apparatus capable of printing on the entire surface of a recording sheet without increasing the cost. And

[0008]

In order to solve the above-mentioned problems of the prior art, the present invention transfers the ink applied to the ink film to the intermediate transfer film by the first heating unit to form an ink image. In a thermal transfer printing apparatus in which the ink image transferred to the intermediate transfer film is retransferred to an image receiver by a second heating unit, immediately after the second heating unit on the downstream side in the transport direction of the intermediate transfer film. A pair of nipping guides for nipping the intermediate transfer film and the image receiving body that are conveyed in close contact with each other with a slight gap, and a pair of rollers provided near the nipping guide on the downstream side in the carrying direction. The intermediate transfer film that has passed through the holding guide is abruptly changed in its conveying direction by the rear end portion of the holding guide to receive the intermediate transfer film. Together are separated from the body, is a separate image receiving material provides a thermal transfer printing apparatus characterized by being configured to convey by said pair of rollers.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A thermal transfer printing apparatus of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a block diagram showing an embodiment of a thermal transfer printing apparatus of the present invention, and FIG. 2 is an enlarged view of a main part of the thermal transfer printing apparatus of the present invention. 1 and 2, the same parts as those in FIGS. 3 and 4 are designated by the same reference numerals.

In FIG. 1, the ink film 1 faces the platen roller 4 with the ink application surface facing the guide shaft 1.
The conveying path is guided by 5a to 15c and is stretched between the supply reel 5 and the take-up reel 6. The supply reel 5 and the take-up reel 6 are controlled and driven by a drive source (not shown), and back tension is applied to the supply reel 5 by a friction clutch (not shown). The ink film 1 has three colors of meltable yellow (Y), magenta (M), and cyan (C) or yellow (Y), magenta (M), cyan (C), and black ( The four color inks of K) are periodically applied. Intermediate transfer film 7
Is guided by the guide shafts 16a to 16f to be stretched between the supply reel 8 and the take-up reel 9. The supply reel 8 and the take-up reel 9 are controlled and driven by a drive source (not shown).

A thermal head 3, which is a first heating unit, is arranged on the lower side (base film side) of the ink film 1 in the figure, and the ink film 1 and the intermediate transfer film are arranged between the thermal head 3 and the platen roller 4. And 7 are in close contact. A heating roller 11 and a retransfer roller 17, which are second heating units, are provided downstream of the first heating unit in the transport direction of the intermediate transfer film 7. Passing between the transfer roller 17,
It is taken up by the take-up reel 9 through a space between the pair of holding guides 18a, 18b which are arranged with a slight gap forming the essential part of the present invention. A thermal head, a ceramic heater, or the like can be used instead of the heating roller 11.

A hopper 20 is provided at the left end in the drawing for storing, for example, cards as recording paper 2, and the recording paper 2 in the hopper 20 is fed by a paper feed roller 21. The recording paper 2 taken out of the hopper 20 is sequentially conveyed by the conveying rollers 22a to 22d and sent between the heating roller 11 and the retransfer roller 17.
When an ink image is transferred from the intermediate transfer film 7 to the recording paper 2 by a series of recording operations described later in detail, the recording paper 2 is always pressed against each other by a spring or the like at a set pressure. The conveying rollers 19a, 19b. Is discharged by.

Next, the recording operation on the recording medium 2 will be described. First, in the initial state, the thermal head 3 is sufficiently separated from the platen roller 4, and the ink film 1 is cued by the ink film mark sensor 23. The first color Y ink is cueed, and a print instruction from a host computer (not shown) is waited for. When an instruction is given from the host computer, the thermal head 3 presses the platen roller 4 by a pressing mechanism (not shown), and the Y ink is transferred to the intermediate transfer film 7 while rotating the platen roller 4. After the transfer of Y ink is completed, the thermal head 3 is moved to the platen roller 4
With further separation, M ink, which is the second color of the ink film 1, is cued. In addition, the intermediate transfer film 7 is accurately wound by counting pulses of an encoder (not shown) provided in the drive system of the platen roller 4 or by using a stepping motor as a drive source and using the number of steps. return.

At this time, the guide shafts 16b and 16c of the intermediate transfer film 7 are set so that the wrapping angle of the intermediate transfer film 7 with respect to the platen roller 4 is 120 ° or more. By the frictional force between the outer peripheral surface and the intermediate transfer film 7, the intermediate transfer film 7
Is rewound without slipping on the platen roller 4. As described above, the intermediate transfer film 7 is reciprocated three times or four times and the inks of three colors or four colors are superposed and transferred, whereby the intermediate transfer film 7 is transferred.
An image (ink image) such as a full-color picture or character is formed on the top.

Next, the take-up reel 9 for the intermediate transfer film 7 is rotated to convey the ink image to the heating roller 11 as follows. When the intermediate transfer film 7 is conveyed to the heating roller 11, the heating roller 11 is separated from the retransfer roller 17. By detecting the head position of the ink image by the intermediate transfer film sensor 24 and counting the moving distance of the intermediate transfer film 7 by the encoder of the drive system of the platen roller 4, the full-color image transferred on the intermediate transfer film 7 is counted. The ink image is moved to just below the heating roller 11. Simultaneously with this operation, the recording sheet 2 such as a card stored in the hopper 20 is taken out by a sheet feeding roller 21 driven by a drive system (not shown) and a separating mechanism (not shown).
Further, it is moved to just below the heating roller 11 by the transport rollers 22a to 22d. Reference numeral 25 is a recording paper sensor.

When the alignment of the leading edge of the ink image on the intermediate transfer film 7 and the leading edge of the recording paper 2 is completed and both are stopped, the heating roller 11 is pressed against the retransfer roller 17 by a pressing mechanism (not shown). Retransfer roller 17
Is rotated at a constant speed to bring the intermediate transfer film 7 and the recording paper 2 into close contact with each other and convey them. At this time, the ink image formed on the intermediate transfer film 7 is melted by the heat of the heating roller 11 and re-transferred onto the recording paper 2. When the ink image portion of the intermediate transfer film 7 and the recording paper 2 pass through the heating roller 11, they both pass between the sandwiching guides 18a and 18b. At this time, the ink image retransferred onto the recording paper 2 is naturally cooled. As can be seen from FIG. 2A, the intermediate transfer film 7 is steeply pulled upward at the rear end of the sandwiching guide 18a, and the transport direction is rapidly changed. As a result, the intermediate transfer film 7 is reliably separated from the recording paper 2. The separated recording paper 2 is fed by the transport rollers 19a, 1
It is pinched by 9b and guided to the paper exit.

Here, the sandwiching guides 18a and 18b will be further described. As shown in FIG. 2 (A), it is necessary to narrow the gap between the sandwiching guides 18a and 18b. Figure 2
As shown in (B), when the distance t between the holding guides 18a and 18b is too wide or there is no lower holding guide 18b, when a thin card such as a telephone card is used as the recording paper 2, Cannot maintain the attitude of the card, and the recording sheet 2 is pulled up together with the intermediate transfer film 7, making separation impossible. According to experiments conducted by the present inventors, by setting the distance t between the holding guides 18a and 18b within 8 times the thickness of the recording sheet 2, the recording sheet 2 is conveyed while the posture of the recording sheet 2 is maintained.
It was confirmed that it was possible to lead to a, 19b.
According to the present invention, not only a rigid card such as a credit card but also a thin card such as a telephone card or a postcard can be used as the recording paper 2 and the intermediate transfer film 7 and the recording paper 2 can be separated well.

[0018]

As described in detail above, the thermal transfer printing apparatus of the present invention is configured so that the intermediate transfer film and the image receiving member which are conveyed in close contact with each other are provided immediately after the downstream side of the second heating portion in the conveying direction of the intermediate transfer film. A pair of nipping guides for nipping (recording paper) with a slight gap, and a pair of rollers provided in the vicinity of the nipping guide on the downstream side in the conveying direction, for nipping the intermediate transfer film that has passed through the nipping guides. Since the intermediate transfer film is separated from the image receiving member by abruptly changing the conveying direction by the rear end portion of the guide, and the separated image receiving member is conveyed by a pair of rollers, the front end of the image receiving member is held. Since it is not necessary, printing can be performed on the entire surface of the recording paper, and because it does not require a costly mechanism such as an air compressor, it can be realized at low cost. A.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is an enlarged view of a main part of the present invention.

FIG. 3 is a configuration diagram showing a conventional example.

FIG. 4 is a partial configuration diagram showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ink film 2 Recording paper (image receiving body) 3 Thermal head (1st heating part) 4 Platen roller 5 Supply reel 6 Take-up reel 7 Intermediate transfer film 8 Supply reel 9 Take-up reel 11 Heating roller (Second heating part) 17 Retransfer Rollers 18a, 18b Clamping Guides 19a, 19b, 22a-22d Conveying Rollers

Claims (1)

[Claims] 1. A first ink applied to an ink film.
In the thermal transfer printing apparatus, an ink image is formed by transferring to the intermediate transfer film by the heating unit of the second transfer unit, and the ink image transferred to the intermediate transfer film is retransferred to an image receiver by the second heating unit. Immediately after the downstream side of the intermediate transfer film in the transport direction of the second heating unit, a pair of sandwiching guides sandwiching the intermediate transfer film and the image receiving body which are transported in close contact with a slight gap, and a pair of sandwiching guides. A pair of rollers provided in the vicinity of the downstream side in the transport direction, and the intermediate transfer film that has passed through the sandwiching guide is abruptly changed in transport direction by the rear end portion of the sandwiching guide. Is separated from the image receiving body, and the separated image receiving body is conveyed by the pair of rollers. Printing device.